With an increasing global demand for agricultural products and farmland, a strategy is urgently needed to preserve land for natural ecosystems and wildlife habitats.
According to a study from the International Institute for Applied Systems Analysis (IIASA), high-yield farming would require only about half the land that is currently used for growing crops.
The research is the first of its kind to provide insight into the amount of cropland needed to satisfy growing demands through the highly-efficient use of land.
Conservation biologists emphasize that there is a limit to how much farmland can be kept “wildlife friendly” without compromising crop yields. Most threatened species can only recover if land is available to restore their natural ecosystems.
The Half Earth project, created by the E.O. Wilson Biodiversity Foundation, aims to return half of the land and sea back to wildlife habitats. The new research shows that nearly half of the land dedicated to farming could be spared.
Study lead author Christian Folberth is a researcher in the IIASA Ecosystems Services and Management Program.
“The main questions we wanted to address were how much cropland could be spared if attainable crop yields were achieved globally and crops were grown where they are most productive. In addition, we wanted to determine what the implications would be for other factors related to the agricultural sector, including fertilizer and irrigation water requirements, greenhouse gas emissions, carbon sequestration potential, and wildlife habitat available for threatened species,” explained Folberth.
According to the study findings, high nutrient inputs and the reallocation of crops on present cropland would make it possible to produce the same yields of major crops with only about 50 percent of the present cropland. Ideally, the remaining land could be used to restore natural landscapes and wildlife habitats.
Overall, current land use was found to be somewhat inefficient, and this lack of productivity was strongly tied to management decisions.
The researchers also determined that with a reduced area of cultivated land, greenhouse gas emissions and irrigation water requirements will likely decrease.
Project lead Michael Obersteiner is the former IIASA Ecosystems Services and Management Program Director.
“The results of our study can help policymakers and the wider public to benchmark results of integrated land use scenarios. It also shows that cropland expansion is not inevitable and that there is significant potential for improving present land use efficiency,” said Obersteiner.
“If the right policies are implemented, measures such as improved production technologies can be just as effective as demand-side measures like dietary changes,” says project lead and “However, in all cases such a process would need to be steered by policies to avoid unwanted outcomes.”
The study is published in the journal Nature Sustainability.